1816.] SEDGWICK ON THE SLATE ROCKS OF CUMBERLAND, ETC. 119 



it ends near Kirkby Lonsdale with a tilestone (5 c), the upper part of 

 which (on the banks of the Lune) contains red calcareous concretions, 

 immediately under Red Scar (old red sandstone). The map and the 

 accompanying section (diagram 11) will explain the manner in which 



11. Section from Kendal toCASTERXON Fell*. 



S.E. 



Lune R. Casterton Fell. 



Faults 



Fault. Craven Fault. 



this formation has been shattered into vast fragmentary masses. The 

 collocation of the masses can only be explained by the interference of 

 two or more lines of dislocation. But among all these dislocations, 

 we may often trace the rudiments of the original north-east strike 

 of the Lake mountains. As far as I know the sections, no older 

 beds are brought up between Kendal and Kirkby Lonsdale. I have 

 not at Lupton Fell, or anywhere else in this district, seen a trace of 

 the groups of (No. 4) : all here is Upper Ludlow. I may here call at- 

 tention to a patch of mountain limestone (at High Bendrigg) which 

 has been laid bare by the bursting of the canal reservoir, and is a 

 striking instance of the vast denudations and convulsions which 

 have affected this singularly broken region. A large list of fossils 

 obtained from this sub-group has already been given, and I could 

 now add considerably to it. In one word, then, the whole fossilife- 

 rous series above-described begins with rocks of the Lower Silurian 

 type, which are only a few hundred feet thick (200 or 300 feet on 

 the average, and 600 feet at the maximum), of the age of Llan- 

 saintffraid and Mathyrafalbeds, and these are not, as I once supposed, 

 on the parallel of the Bala limestone. All the other rocks are Upper 

 Silurian, and there is no unconformable overlap of Windermere 

 rocks to be distinguished from the general series from No. 2 up to 

 No. 5. The subdivisions of the groups do not resemble those of 

 Siluria, neither does the minute arrangement of the species ; but 

 there is a general resemblance amongst the species and Upper Siluria 

 and Westmoreland, which considered as one great group, are almost 

 identical, and both end with the same mineral type, viz. a red flag- 

 stone or tilestone. 



Lastly, the development of the Upper Silurian series (not resem- 

 bling that observed in Siluria) does, on the other hand, resemble that 

 in South Wales, nine-tenths of the higher slate mountains of which, 

 I doubt not, will prove Upper Silurian. 



* In this diagram the number (5) refers to the upper sub-group (5 b), and tlie 

 lines projecting beyond the outUne of the section represent the faults. The num- 

 ber 8 refers to the great limestone shale (' Yoredale series ' of Phillips), and num- 

 ber 9 to the lowest millstone grit. 



